Design for a mounting bracket for a trailer jack



FIG. 1 is a front elevational view of a design for a mounting bracketfor a trailer jack showing my new design;

FIG. 2 is a perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof; and

FIG. 6 is a rear elevational view thereof.

The broken line showing of a trailer jack is for illustrative purposesonly and forms no part of the claimed design.

The ornamental design for a mounting bracket for a trailer jack, asshown and described.